Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (8,377)	$ (2,737)	$ (13,764)	$ (7,522)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization			499	454
Share-based compensation			302	11
Change in fair value of warrant liability	5,549		5,549
Deferred rent			(1)	3
Changes in operating assets and liabilities:
Prepaid expenses and deferred IPO costs and other assets			(151)	(249)
Accounts payable			999	334
Accrued expenses and other current liabilities			495	(52)
Net cash used in operating activities			(6,072)	(7,021)
Cash flows from investing activities:
Purchases of property and equipment			(540)	(166)
Net cash used in investing activities			(540)	(166)
Cash flows from financing activities:
Proceeds from convertible promissory notes				6,800
Proceeds from exercise of stock options			7
Proceeds from long-term debt			500
Proceeds from the sale of Series A convertible preferred stock			11,046
Payment of IPO costs			(309)
Payment of Series A convertible preferred stock issuance costs			(27)
Payment of equipment loan payable			(165)	(183)
Payment of capital lease obligations			(239)	(272)
Net cash provided by financing activities			10,813	6,345
Net increase (decrease) in cash and restricted cash			4,201	(842)
Cash and restricted cash at beginning of period			2,643	1,702	$ 1,702
Cash and restricted cash at end of period	$ 6,844	$ 860	6,844	860	$ 2,643
Supplemental disclosures of cash flow information:
Cash paid for interest			27	$ 72
Supplemental disclosures of non-cash investing and financing activities:
Fair value of liability-classified warrants issued in connection with Series A convertible preferred stock			1,522
Series A convertible preferred stock and warrants issuance costs in accounts payable			22
IPO costs included in accounts payable and accrued expenses and other current liabilities			$ 2,221